Large-area van der Waals epitaxy and magnetic characterization of Fe3GeTe2films on graphene

Scalable fabrication of magnetic 2D materials and heterostructures constitutes a crucial step for scaling down current spintronic devices and the development of novel spintronic applications. Here, we report on van der Waals (vdW) epitaxy of the layered magnetic metal Fe3GeTe2 (FGT) - a 2D crystal with highly tunable properties and a high prospect for room temperature ferromagnetism (FM) - directly on graphene by employing molecular beam epitaxy. Morphological and structural characterization confirmed the realization of large-area, continuous FGT/graphene heterostructure films with stable interfaces and good crystalline quality. Furthermore, magneto-transport and x-ray magnetic circular dichroism investigations confirmed a robust out-of-plane FM in the layers, comparable to state-of-the-art exfoliated flakes from bulk crystals. These results are highly relevant for further research on wafer-scale growth of vdW heterostructures combining FGT with other layered crystals such as transition metal dichalcogenides for the realization of multifunctional, atomically thin devices.They also acknowledge the provision of beamtime under the project HC-4068 at the European Synchrotron Radiation Facility (ESRF), located in Grenoble (France). ICN2 researchers acknowledge support from the European Union Horizon 2020 research and innovation programme under Grant Agreement No. 881603 (Graphene Flagship)

Large-area van der Waals epitaxy and magnetic characterization of Fe3GeTe2films on graphene

Scalable fabrication of magnetic 2D materials and heterostructures constitutes a crucial step for scaling down current spintronic devices and the development of novel spintronic applications. Here, we report on van der Waals (vdW) epitaxy of the layered magnetic metal Fe3GeTe2 (FGT) - a 2D crystal with highly tunable properties and a high prospect for room temperature ferromagnetism (FM) - directly on graphene by employing molecular beam epitaxy. Morphological and structural characterization confirmed the realization of large-area, continuous FGT/graphene heterostructure films with stable interfaces and good crystalline quality. Furthermore, magneto-transport and x-ray magnetic circular dichroism investigations confirmed a robust out-of-plane FM in the layers, comparable to state-of-the-art exfoliated flakes from bulk crystals. These results are highly relevant for further research on wafer-scale growth of vdW heterostructures combining FGT with other layered crystals such as transition metal dichalcogenides for the realization of multifunctional, atomically thin devices

Cervical pregnancy in assisted reproduction: an analysis of risk factors in 91,067 ongoing pregnancies

OBJECTIVE: To assess the frequency of cervical pregnancy (CP) in women undergoing assisted reproductive techniques (ART) and to ascertain its risk factors DESIGN: Case-control study. Two control groups were established: tubal ectopic pregnancies and intrauterine pregnancies. SETTING: 25 private assisted reproduction clinics run by the same group in Spain PATIENT(S): Women undergoing ART (artificial insemination, or IVF with own or donor oocytes). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Frequency of CP. Ascertainment of demographic and clinical risk factors. Assessment of the influence of IVF parameters on CP risk. RESULT(S): There were 32 CPs out of 91,067 ongoing pregnancies, yielding a rate of 3.5/10,000. CPs represented 2.02% of all ectopic pregnancies (32/1582). The main risk factors were: ≥ 2 previous pregnancies (OR= 2.68; CI=1.18-6.07), ≥2 previous miscarriages (OR= 4.21, CI=1.7- 10.43), ≥ 2 previous curettages (OR=4.71; CI= (1.19-18.66) and smoking (OR= 2.82 (1.14-6.94). History of cesarean sections and tubal pregnancy were not associated with an elevated CP risk. Infertility conditions and endometrial thickness were similar across the three groups. The proportion of women from whom < 10 oocytes were retrieved was higher in the CP group than in either of the control groups. CONCLUSION(S): In ART, the main risk factors for ectopic pregnancy are a history of at least 2 pregnancies/miscarriages/curettages, and smoking. IVF parameters do not seem to influence the development of CP. CP is less common in ART than previously reported, likely attributable to improvements in ART, although a publication bias cannot be ruled out in early IVF reports

Large-area van der Waals epitaxy and magnetic characterization of Fe3GeTe2 films on graphene

Scalable fabrication of magnetic 2D materials and heterostructures constitutes a crucial step for scaling down current spintronic devices and the development of novel spintronic applications. Here, we report on van der Waals (vdW) epitaxy of the layered magnetic metal Fe3GeTe2 (FGT) - a 2D crystal with highly tunable properties and a high prospect for room temperature ferromagnetism (FM) - directly on graphene by employing molecular beam epitaxy. Morphological and structural characterization confirmed the realization of large-area, continuous FGT/graphene heterostructure films with stable interfaces and good crystalline quality. Furthermore, magneto-transport and x-ray magnetic circular dichroism investigations confirmed a robust out-of-plane FM in the layers, comparable to state-of-the-art exfoliated flakes from bulk crystals. These results are highly relevant for further research on wafer-scale growth of vdW heterostructures combining FGT with other layered crystals such as transition metal dichalcogenides for the realization of multifunctional, atomically thin devices. © 2021 The Author(s)